U.S. patent application number 16/766968 was filed with the patent office on 2021-02-04 for user terminal and radio communication method.
This patent application is currently assigned to NTT DOCOMO, INC.. The applicant listed for this patent is NTT DOCOMO, INC.. Invention is credited to Satoshi Nagata, Kazuki Takeda, Lihui Wang, Shohei Yoshioka.
Application Number | 20210036835 16/766968 |
Document ID | / |
Family ID | 1000005166321 |
Filed Date | 2021-02-04 |
United States Patent
Application |
20210036835 |
Kind Code |
A1 |
Yoshioka; Shohei ; et
al. |
February 4, 2021 |
USER TERMINAL AND RADIO COMMUNICATION METHOD
Abstract
To appropriately control CSI reporting even when CSI reporting
is performed by applying a method different from a method used in
existing LTE systems. A user terminal includes: a receiving section
that receives downlink control information indicating activation or
deactivation of semi-persistent channel state information; and a
control section that controls transmission of the semi-persistent
channel state information by making an interpretation of a certain
bit field included in the downlink control information based on an
RNTI applied to a CRC of the downlink control information.
Inventors: |
Yoshioka; Shohei; (Tokyo,
JP) ; Takeda; Kazuki; (Tokyo, JP) ; Nagata;
Satoshi; (Tokyo, JP) ; Wang; Lihui; (Beijing,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NTT DOCOMO, INC. |
Tokyo |
|
JP |
|
|
Assignee: |
NTT DOCOMO, INC.
Tokyo
JP
|
Family ID: |
1000005166321 |
Appl. No.: |
16/766968 |
Filed: |
November 26, 2018 |
PCT Filed: |
November 26, 2018 |
PCT NO: |
PCT/JP2018/043393 |
371 Date: |
May 26, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 72/0493 20130101;
H04B 7/0626 20130101; H04L 5/0098 20130101; H04L 1/0061 20130101;
H04W 72/042 20130101; H04W 76/11 20180201 |
International
Class: |
H04L 5/00 20060101
H04L005/00; H04B 7/06 20060101 H04B007/06; H04W 72/04 20060101
H04W072/04; H04W 76/11 20060101 H04W076/11; H04L 1/00 20060101
H04L001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 27, 2017 |
JP |
2017-239055 |
Claims
1. A user terminal comprising: a receiving section that receives
downlink control information indicating activation or deactivation
of semi-persistent channel state information; and a control section
that controls transmission of the semi-persistent channel state
information by making an interpretation of a certain bit field
included in the downlink control information based on an RNTI
applied to a CRC of the downlink control information.
2. The user terminal according to claim 1, wherein the control
section changes the interpretation of the certain bit field
included in the downlink control information when a certain RNTI is
applied to the CRC of the downlink control information.
3. The user terminal according to claim 1, wherein the certain bit
field includes a resource allocation field.
4. A radio communication method comprising: receiving downlink
control information indicating activation or deactivation of
semi-persistent channel state information; and controlling
transmission of the semi-persistent channel state information by
making an interpretation of a certain bit field included in the
downlink control information based on an RNTI applied to a CRC of
the downlink control information.
5. The user terminal according to claim 2, wherein the certain bit
field includes a resource allocation field.
Description
TECHNICAL FIELD
[0001] The present invention relates to a user terminal and a radio
communication method in next-generation mobile communication
systems.
BACKGROUND ART
[0002] In UMTS (Universal Mobile Telecommunications System)
networks, the specifications of Long Term Evolution (LTE) have been
drafted for the purpose of further increasing high speed data
rates, providing lower latency and so on (see Non-Patent Literature
1). Further, LTE-A (also referred to as LTE-Advanced, LTE Rel. 10,
Rel. 11, or Rel. 12) has been drafted for the purpose of achieving
a broader bandwidth and higher speed beyond LTE (also referred to
as LTE Rel. 8 or Rel. 9), successor systems of LTE (also referred
to as, for example, "FRA (Future Radio Access)," "5G (5th
generation mobile communication system)," "5G+(plus)," "NR (New
Radio)," "NX (New radio access)," "FX (Future generation radio
access)," "LTE Rel. 13," "LTE Rel. 14," "LTE Rel. 15" (or later
versions), and so on) are also under study.
[0003] In existing LTE systems (for example, LTE Rel. 8 to Rel.
13), an uplink signal is mapped to an appropriate radio resource to
be transmitted from a UE to an eNB. Uplink user data is transmitted
using an uplink shared channel (PUSCH (Physical Uplink Shared
Channel)). Further, uplink control information (UCI) is transmitted
using a PUSCH when the UCI is transmitted together with uplink user
data, and is transmitted using an uplink control channel (PUCCH
(Physical Uplink Control Channel)) when the UCI is transmitted by
itself.
[0004] The UCI includes transmission confirmation information
(ACK/NACK), a scheduling request, and channel state information
(CSI) for a downlink shared channel (PDSCH (Physical Downlink
Shared Channel)), for example. The transmission confirmation
information may be referred to as an HARQ-ACK (Hybrid Automatic
Repeat reQuest-Acknowledgement), an ACK/NACK (A/N), retransmission
control information, and so on.
[0005] The CSI is information based on a downlink instantaneous
channel state, and is, for example, a channel quality indicator
(CQI), a precoding matrix indicator (PMI), a precoding type
indicator (PTI), a rank indicator (RI), and so on. The CSI is
notified from the UE to the eNB either periodically or
aperiodically.
[0006] Periodic CSI (P-CSI) is such CSI that is periodically
transmitted by the UE, based on periodicity and a resource that are
notified from the radio base station. In contrast, aperiodic CSI
(A-CSI) is such CSI that is transmitted by the UE, according to a
CSI report request (also referred to as a trigger, a CSI trigger, a
CSI request, and so on) that is from the radio base station.
[0007] The CSI trigger is included in an uplink scheduling grant
(hereinafter also referred to as a UL (Uplink) grant) that is
transmitted on a downlink control channel (PDCCH (Physical Downlink
Control Channel)). In accordance with a CSI trigger included in a
UL grant for scheduling uplink data, the UE gives a notification of
A-CSI by using a PUSCH that is designated by the UL grant. Such
notification is also referred to as A-CSI reporting.
CITATION LIST
Non-Patent Literature
[0008] Non-Patent Literature 1: 3GPP TS 36.300 V8.12.0 "Evolved
Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal
Terrestrial Radio Access Network (E-UTRAN); Overall description;
Stage 2 (Release 8)," April, 2010
SUMMARY OF INVENTION
Technical Problem
[0009] For future radio communication systems (for example, LTE
Rel. 14, Rel. 15 or later versions, 5G, NR, and so on), control of
CSI reporting using a configuration different from a configuration
used in the existing LTE systems (for example, LTE Rel. 13 or
earlier versions) is also under study.
[0010] For example, aperiodic CSI reporting performed by using an
uplink control channel as well as an uplink shared channel is under
study. In this case, how to control allocation of an uplink control
channel to allocate aperiodic CSI presents a problem.
[0011] For example, one possible solution is to apply control
similar to control of CSI reporting in the existing systems. In the
existing systems, triggers of A-CSI reporting are controlled using
a PUSCH that is designated by a UL grant for scheduling uplink
data; however, designation of a resource of an uplink control
channel using a UL grant is not assumed. As described above, when
CSI reporting is performed by applying a method different from a
method used in the existing LTE systems, directly applying the
method of controlling CSI reporting of the existing LTE systems may
be impractical.
[0012] The present invention is made under the circumstances as
described above, and has one object to provide a user terminal and
a radio communication method that can appropriately control CSI
reporting even when CSI reporting is performed by applying a method
different from a method used in existing LTE systems.
Solution to Problem
[0013] A user terminal according to one aspect of the present
invention includes: a receiving section that receives downlink
control information indicating activation or deactivation of
semi-persistent channel state information; and a control section
that controls transmission of the semi-persistent channel state
information by making an interpretation of a certain bit field
included in the downlink control information according to an RNTI
applied to a CRC of the downlink control information.
Advantageous Effects of Invention
[0014] According to the present invention, CSI reporting can be
appropriately controlled even when CSI reporting is performed by
applying a method different from a method used in existing LTE
systems.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a diagram to show an example of transmission of
A-CSI in existing systems;
[0016] FIG. 2 is a diagram to show an example of A-CSI using a
PUCCH;
[0017] FIGS. 3A and 3B are each a diagram to show an example of DCI
for triggering A-CSI;
[0018] FIG. 4 is a diagram to show another example of DCI for
triggering A-CSI;
[0019] FIG. 5 is a diagram to show an example of a schematic
structure of a radio communication system according to one
embodiment of the present invention;
[0020] FIG. 6 is a diagram to show an example of an overall
structure of a radio base station according to one embodiment of
the present invention;
[0021] FIG. 7 is a diagram to show an example of a functional
structure of the radio base station according to one embodiment of
the present invention;
[0022] FIG. 8 is a diagram to show an example of an overall
structure of a user terminal according to one embodiment of the
present invention;
[0023] FIG. 9 is a diagram to show an example of a functional
structure of the user terminal according to one embodiment of the
present invention; and
[0024] FIG. 10 is a diagram to show an example of a hardware
structure of the radio base station and the user terminal according
to one embodiment of the present invention.
DESCRIPTION OF EMBODIMENTS
[0025] In the existing LTE systems (Rel. 10 to Rel. 13), a
reference signal for measuring a channel state in the downlink is
defined. The reference signal for channel state measurement is also
referred to as a CRS (Cell-specific Reference Signal) and a CSI-RS
(Channel State Information-Reference Signal), and is a reference
signal used to measure CSI as a channel state, such as a CQI
(Channel Quality Indicator), a PMI (Precoding Matrix Indicator),
and an RI (Rank Indicator).
[0026] A user terminal (UE) feeds results measured based on the
reference signal for channel state measurement back to a radio base
station as channel state information (CSI) at certain timing. As
CSI feedback methods, periodic CSI reporting (P-CSI) and aperiodic
CSI reporting (A-CSI) are defined.
[0027] When the UE performs aperiodic CSI reporting, the UE
performs transmission of A-CSI according to a CSI trigger (CSI
request) from the radio base station. For example, the UE performs
A-CSI reporting after the elapse of certain timing (for example,
four subframes) from reception of the CSI trigger.
[0028] The CSI trigger notified from the radio base station is
included in downlink control information (for example, DCI format
0/4) for an uplink scheduling grant (UL grant) transmitted on a
downlink control channel. The UE performs A-CSI transmission by
using a PUSCH designated by the UL grant, according to the trigger
included in the downlink control information for a UL grant for
scheduling UL data (see FIG. 1). Further, when CA is applied, the
user terminal can receive a UL grant (including an A-CSI trigger)
for a certain cell on a downlink control channel of another
cell.
[0029] Incidentally, for future radio communication systems (also
referred to as 5G/NR), performance of CSI reporting in a
configuration different from a configuration used in the existing
LTE systems is under study. For example, performing A-CSI reporting
by using a PUCCH as well as a PUSCH is under study (see FIG. 2).
FIG. 2 shows a case in which A-CSI is transmitted by using a short
PUCCH and/or a long PUCCH based on an indication (CSI trigger) from
the base station.
[0030] The short PUCCH corresponds to a UL control channel that can
use short duration compared to duration of a PUCCH format of the
existing LTE systems (for example, LTE Rel. 8 to Rel. 13). Further,
the long PUCCH corresponds to a UL control channel having long
duration compared to the short duration of the short PUCCH. The
short PUCCH includes a certain number of symbols (for example, one,
two, or three symbols) in a certain sub-carrier spacing (SCS). In
the short PUCCH, uplink control information and a reference signal
may be multiplexed in time division multiplexing (TDM), or may be
multiplexed in frequency division multiplexing (FDM). The RS may
be, for example, a demodulation reference signal (DMRS) used to
demodulate UCI. The short PUCCH may be configured in at least one
symbol of each slot.
[0031] In contrast, the long PUCCH is mapped over a plurality of
symbols in a slot in order to further enhance coverage and/or
transmit a larger amount of UCI than the short PUCCH. For example,
the long PUCCH may be configured using 7 symbols or 14 symbols. In
the long PUCCH, UCI and an RS (for example, a DMRS) may be
multiplexed in TDM, or may be multiplexed in FDM. In the long
PUCCH, frequency hopping may be applied to each certain period (for
example, mini-(sub-)slot) in a slot. When intra-slot frequency
hopping is applied in a slot, it is preferable that a DMRS of one
or two symbols be mapped in each hop.
[0032] The long PUCCH may include as many frequency resources as
the short PUCCH, or may include less frequency resources (for
example, one or two physical resource blocks (PRBs)) than the short
PUCCH to achieve a power amplification effect. Further, the long
PUCCH may be mapped in the same slot as the short PUCCH.
[0033] Note that when a plurality of PUCCH formats are supported,
the short PUCCH may correspond to a certain PUCCH format (for
example, PUCCH format 0 or 2), and the long PUCCH may correspond to
another PUCCH format (for example, PUCCH format 1, 3, or 4).
[0034] Accepting (supporting) A-CSI using a PUCCH as described
above allows for flexible control of CSI reporting and enhancement
of quality of transmission and reception of A-CSI. In contrast, in
the existing systems, A-CSI reporting is controlled using a PUSCH
designated by a UL grant for scheduling uplink data, and
designation of PUCCH resources using a UL grant is not assumed.
[0035] Accordingly, when A-CSI reporting using a PUCCH is supported
as well as A-CSI reporting using a PUSCH, how the UE controls a UL
channel used to perform transmission of A-CSI presents a
problem.
[0036] The inventors of the present invention focused on that
transmission indication of channel state information is performed
using downlink control information, and came up with the idea of
adopting a configuration in which an uplink channel to be used for
transmission of channel state information is determined based on
the downlink control information.
[0037] Embodiments according to the present invention will be
described in detail with reference to the drawings as follows. A
configuration illustrated in an aspect of each embodiment may be
employed independently or may be employed in combination. Further,
although the following description assumes an aperiodic CSI (A-CSI)
trigger, the present embodiment is not limited to such a
configuration. For example, the present embodiment is also
applicable to a notification of activation and/or deactivation of
CSI (for example, semi-persistent CSI). In this case, a "trigger of
CSI" may be replaced with a "notification of activation and/or
deactivation of CSI (for example, SP-CSI)".
[0038] Note that the SP-CSI implies a case in which CSI reporting
is semi-persistently performed (SP-CSI (Semi-persistent CSI)). In
SP-CSI reporting, at least one of a wide band, a partial band, and
a subband is used as frequency granularity, a long PUCCH and/or
PUSCH is used as a physical channel, and type 1-CSI and/or partial
type 2 CSI is used as a codebook. When CSI reporting is
semi-persistently performed, configuration (for example, activation
and/or deactivation) for the UE can be performed by using downlink
control information and/or MAC control information (MAC CE).
(First Aspect)
[0039] The first aspect illustrates a case in which determination
of a UL channel to be used for transmission of channel state
information (CSI) is controlled based on downlink control
information (DCI). The DCI may be DCI for triggering the CSI.
Further, although the following description assumes a case in which
an uplink shared channel (PUSCH) and a short PUCCH (sPUCCH) are
used as UL channels, applicable UL channels are not limited to
those described above. A short PUSCH or an uplink control channel
(PUCCH) may be used for transmission of CSI.
[0040] When a CSI trigger is indicated from the base station, the
UE determines a UL channel to be used for transmission of CSI,
based on certain DCI. The certain DCI may be DCI for indicating a
CSI trigger, or may be other DCI. Further, as the certain DCI, at
least one of a UL grant for indicating UL transmission (UL data
scheduling), a DL assignment for indicating DL transmission (DL
data scheduling), and DCI for indicating a CSI trigger without
scheduling data (also referred to as DCI for CSI trigger) can be
used.
[0041] For example, the UE determines whether CSI transmission is
performed on a PUSCH or an sPUCCH, based on a bit field included in
certain DCI, an RNTI applied to certain DCI, and a size of certain
DCI. Each of the cases using a bit field, an RNTI, and a DCI size
will be described below.
<Bit Field>
[0042] When a CSI trigger is indicated, the UE determines an uplink
channel to allocate CSI, based on a value of a specific bit field
included in certain DCI. The specific bit field includes one bit or
a plurality of bits.
[0043] FIGS. 3A and 3B each show an example of DCI of a case in
which a field (here, 1-bit field) designating an uplink channel is
provided in DCI for indicating a CSI trigger. FIG. 3A shows a case
in which a field for UL channel identification is provided in DCI
(for example, a UL grant) for scheduling data. FIG. 3B shows a case
in which a field for UL channel identification is provided in DCI
for CSI trigger.
[0044] The DCI for data scheduling (a UL grant or a DL assignment)
may include a CSI trigger field. In contrast, when the DCI for CSI
trigger is supported, the DCI for CSI trigger may not include a CSI
trigger field (see FIG. 3B).
[0045] For example, when a value of the field for UL channel
identification in DCI for indicating a CSI trigger is "0", the UE
performs CSI reporting (CSI transmission) by using the PUSCH. In
contrast, when a value of the field for UL channel identification
in DCI for indicating a CSI trigger is "1", the UE performs CSI
reporting (CSI transmission) by using the sPUCCH.
[0046] Further, a combination candidate set of a UL channel and a
transmission condition (transmission parameter) used for CSI
reporting may be configured for (or notified to) the UE from the
base station in advance, and a specific candidate set may be
determined by using DCI. Information related to the candidate set
may be configured for the UE from the base station in advance by
means of higher layer signaling (for example, RRC signaling and so
on). Further, bit information used for notification of the specific
candidate set may be configured in a certain bit field of the DCI
(for example, a field for UL channel identification and so on).
[0047] Further, the UE may control an interpretation of other bit
fields included in the DCI, based on bit information of the field
for UL channel identification. Examples of such other bit fields
may include a resource allocation field (RA field) and/or a power
control field (TPC field).
[0048] For example, when the field for UL channel identification
indicates a PUSCH (when the field indicates "0"), the UE controls
allocation of the PUSCH and/or the CSI, based on an RA field
indicating resource allocation and included in the DCI (for
example, a UL grant). In other words, when a CSI trigger using the
PUSCH is indicated using DCI, the UE determines that a resource
allocation field included in the DCI is a field for PUSCH
transmission, and controls allocation of the CSI.
[0049] When the field for UL channel identification indicates a
PUCCH (when the field indicates "1"), the UE controls allocation of
the sPUCCH and/or the CSI, based on an RA field indicating resource
allocation and included in the DCI (for example, a UL grant). In
other words, when a CSI trigger using the PUCCH is indicated using
DCI, the UE determines that a resource allocation field included in
the DCI is a field for PUCCH transmission, and controls allocation
of the CSI.
[0050] Alternatively, when the field for UL channel identification
indicates a PUSCH (when the field indicates "0"), the UE applies
information notified in a power control command (TPC) field to
PUSCH transmission. In other words, when a CSI trigger using the
PUSCH is indicated using DCI, the UE determines that a TPC field
included in the DCI is a field for PUSCH transmission, and controls
transmission power of the PUSCH to be used to transmit the CSI.
[0051] When the field for UL channel identification indicates a
PUCCH (when the field indicates "1"), the UE applies information
notified in a power control command (TPC) field to PUCCH
transmission. In other words, when a CSI trigger using the PUCCH is
indicated using DCI, the UE determines that a TPC field included in
the DCI is a field for PUCCH transmission, and controls
transmission power of the PUCCH to be used to transmit the CSI.
[0052] Further, when TPC command accumulation is applied, the UE
may control TPC command accumulation, based on bit information of
the field for UL channel identification. For example, when the
field for UL channel identification indicates a PUSCH (when the
field indicates "0"), the UE performs TPC command accumulation as
TPC for the PUSCH. In contrast, when the field for UL channel
identification indicates a PUCCH (when the field indicates "1"),
the UE performs TPC command accumulation as TPC for the PUCCH.
[0053] In this manner, transmission power of each uplink channel
can be flexibly controlled also in consideration of aperiodically
transmitted CSI transmission. For example, when PUCCH transmission
is performed after performing CSI transmission using the PUCCH,
transmission power of the PUCCH transmission after the CSI
transmission can be determined based on a communication environment
by also accumulating TPC commands at the time of the CSI
transmission.
[0054] In this manner, by giving a notification of an uplink
channel to be used for CSI reporting with the use of a bit field
included in certain DCI from the base station to the UE, an uplink
channel to be used for CSI transmission can be flexibly changed and
controlled for each CSI trigger.
[0055] Note that a DCI format size (payload size) of DCI for
triggering CSI reporting using the PUSCH may be the same as a DCI
format size of DCI for triggering CSI reporting using the PUCCH. In
this manner, the same error correction code (for example, a polar
code) can be applied to each piece of DCI. As a result, processing
of transmission and reception processing can be simplified and
increase of a processing load can be prevented.
[0056] Further, an RNTI used for masking a CRC of the DCI for
triggering CSI reporting using the PUSCH and an RNTI used for
masking a CRC of the DCI for triggering CSI reporting using the
PUCCH may be the same. In this manner, the same RNTI can be applied
to the pieces of DCI, and thus a load of transmission and reception
processing can be prevented from increasing.
[0057] Further, either a search space of the DCI for triggering CSI
reporting using the PUSCH or a search space of the DCI for
triggering CSI reporting using the PUCCH may include the other. For
example, the search space of the DCI for triggering CSI reporting
using the PUSCH may be configured to be the same as the search
space of the DCI for triggering CSI reporting using the PUCCH.
Further, the search space of the DCI for triggering CSI reporting
using the PUSCH may be configured to be a subset or a superset of
the search space of the DCI for triggering CSI reporting using the
PUCCH.
[0058] In this manner, by adopting the configuration in which
either the search space of the DCI for triggering CSI reporting
using the PUSCH or the search space of the DCI for triggering CSI
reporting using the PUCCH includes the other, downlink control
channel candidates (PDCCH candidates) corresponding to respective
pieces of DCI may be configured in common. In this manner, a range
that the UE monitors (detects) when the UE receives the pieces of
DCI can be prevented from increasing.
<RNTI>
[0059] When a CSI trigger is indicated, the UE may determine an
uplink channel to allocate CSI, based on an RNTI applied to certain
DCI. For example, different RNTIs are applied to DCI for indicating
a CSI trigger using the PUSCH and DCI for indicating a CSI trigger
using the PUCCH.
[0060] In this case, the base station masks a CRC of the DCI for
indicating a CSI trigger using the PUSCH by using a first RNTI (for
example, a specific RNTI), and masks a CRC of the DCI for
indicating a CSI trigger using the PUCCH by using a second RNTI.
Information related to the first RNTI and/or the second RNTI may be
configured for the UE from the base station by means of higher
layer signaling (for example, RRC signaling and so on).
[0061] For example, when a CRC of received DCI is masked using the
first RNTI, the UE performs CSI reporting (CSI transmission) by
using the PUSCH. In contrast, when a CRC of received DCI is masked
using the second RNTI, the UE performs CSI reporting (CSI
transmission) by using the sPUCCH.
[0062] Further, the UE may control an interpretation of other bit
fields included in the DCI, based on a type of an RNTI that is
applied to the DCI (that is used to mask a CRC of the DCI).
Examples of such other bit fields may include a resource allocation
field (RA field) and/or a power control field (TPC field).
[0063] An interpretation method of other bit fields may be
implemented in a similar manner to the above-described case in
which an uplink channel is determined based on a bit field. For
example, in the above description, the case in which the field for
UL channel identification indicates a PUSCH (when the field
indicates "0") corresponds to a case in which a CRC of DCI is
masked using the first RNTI, and the case in which the field for UL
channel identification indicates a PUCCH (when the field indicates
"1") corresponds to a case in which a CRC of DCI is masked using
the second RNTI.
[0064] In this manner, by determining an uplink channel to be used
for CSI reporting with the use of an RNTI applied to DCI for
indicating a CSI trigger, an uplink channel to be used for CSI
transmission can be flexibly changed and controlled for each CSI
trigger. Further, the use of an RNTI used for DCI allows for
notification of an uplink channel to be used for CSI transmission
without increasing the size of DCI (without providing a bit
field).
[0065] When different RNTIs are applied to individual uplink
channels to be used for CSI transmission, different configurations
(for example, non-overlapping configurations) may be adopted for
the search space of the DCI for triggering CSI reporting using the
PUSCH and the search space of the DCI for triggering CSI reporting
using the PUCCH. In this case, probability of blocking, which is a
situation in which both the search spaces contend against each
other for allocable resources and thus either of them is hindered
from resource allocation, can be reduced.
[0066] Alternatively, when different RNTIs are applied to the DCI
for triggering CSI reporting using the PUSCH and the DCI for
triggering CSI reporting using the PUCCH, the same configuration
may be adopted for the search spaces of the respective pieces of
DCI (or a configuration in which either of the search spaces
includes the other may be adopted). In this case, results of
channel estimation and error correction decoding performed in a
single blind detection can be used for blind detection for a
plurality of pieces of DCI, and thus a load of terminal processing
can be reduced.
<DCI Size>
[0067] When a CSI trigger is indicated, the UE may determine an
uplink channel to allocate CSI, based on the size of certain DCI.
For example, DCI for indicating CSI reporting using the PUSCH and
DCI for indicating CSI reporting using the PUCCH are configured to
have different sizes (payload sizes) (see FIG. 4).
[0068] The UE determine whether an uplink channel for performing
CSI reporting is a PUSCH or a PUCCH, based on the size of received
DCI.
[0069] For example, FIG. 4 shows a case in which the size of the
DCI for indicating CSI reporting using the PUSCH is represented by
"X" and the size of the DCI for indicating CSI reporting using the
PUCCH is represented by "Y" (X>Y). The figure shows a case in
which the size of the DCI for indicating CSI reporting using the
PUSCH is larger than the size of the DCI for indicating CSI
reporting using the PUCCH, but this is not restrictive (X and Y may
be X<Y).
[0070] The DCI payload size is determined according to the number
of bits of a bit field included in each piece of DCI. In some
cases, the size of the DCI for indicating CSI reporting using the
PUSCH and the size of the DCI for indicating CSI reporting using
the PUCCH may be assumed to be the same as each other. In this
case, certain bit(s) may be added to either piece of DCI so as to
make a difference in the payload sizes. As the certain bit(s), a
1-bit padding bit corresponding to empty information may be
used.
[0071] Further, the size of a certain field of DCI may be changed,
instead of the size of the entire DCI. For example, a bit size of a
certain field (for example, an RA field) included in the DCI for
indicating CSI reporting using the PUSCH may be configured to be
larger than a bit size of a certain field (for example, an RA
field) included in the DCI for indicating CSI reporting using the
PUCCH. In this case, the sizes of the entire DCI may also be
different.
[0072] Further, the UE may control an interpretation of other bit
fields included in the DCI, based on the size of the DCI (or the
size of a certain field). Examples of such other bit fields may
include a resource allocation field (RA field) and/or a power
control field (TPC field).
[0073] An interpretation method of other bit fields may be
implemented in a similar manner to the above-described case in
which an uplink channel is determined based on a bit field. For
example, in the above description, the case in which the field for
UL channel identification indicates a PUSCH (when the field
indicates "0") corresponds to a case in which the size of DCI is X,
and the case in which the field for UL channel identification
indicates a PUCCH (when the field indicates "1") corresponds to a
case in which the size of DCI is Y.
[0074] Further, when different configurations are adopted for the
size of the DCI for indicating CSI reporting using the PUSCH and
the size of the DCI for indicating CSI reporting using the PUCCH,
different error correction codes (for example, polar codes) may be
applied to the respective pieces of DCI.
[0075] Further, an RNTI used for masking a CRC of the DCI for
indicating CSI reporting using the PUSCH and an RNTI used for
masking a CRC of the DCI for indicating CSI reporting using the
PUCCH may be the same. In this manner, the same RNTI can be applied
to the pieces of DCI, and thus a load of transmission and reception
processing can be prevented from increasing.
[0076] Further, either a search space of the DCI for indicating CSI
reporting using the PUSCH or a search space of the DCI for
indicating CSI reporting using the PUCCH may include the other. For
example, the search space of the pieces of DCI may be configured to
be the same as the search space of the DCI for data scheduling.
Further, the search space of either piece of DCI may be configured
to be a subset or a superset of the search space of the other piece
of DCI.
[0077] In this manner, by determining an uplink channel to be used
for CSI reporting based on the size of DCI for indicating a CSI
trigger, an uplink channel to be used for CSI transmission can be
flexibly changed and controlled for each CSI trigger. Further, by
adopting the configuration in which the DCI for indicating CSI
reporting using the PUSCH and the DCI for indicating CSI reporting
using the PUCCH have different sizes, the size of each piece of DCI
can be flexibly configured according to a purpose of each piece of
DCI.
(Variations)
[0078] The UE may simultaneously receive a plurality of A-CSI
triggers in the same serving cell. For example, the base station
may transmit, to a certain UE, DCI for indicating a plurality of
times of CSI reporting (CSI triggers) in a certain time unit (a
subframe, a slot, a mini-slot, or the like).
[0079] In this case, one of the plurality of triggers may be an
A-CSI trigger using the PUSCH, and the other triggers may be A-CSI
triggers using the short PUCCH. In this case, the UE controls any
one of an uplink channel and a resource to be transmitted and
transmission timing, based on notified DCI.
[0080] Further, the UE may perform CSI reporting by using different
resources (for example, different UL channels) at the same timing
or different timings, based on a plurality of CSI triggers. Note
that a plurality of A-CSI triggers may be individually notified
using a plurality of different pieces of DCI, or may be notified
using one piece of DCI.
[0081] Permitting simultaneous transmission of indications of a
plurality of times of CSI reporting to the UE as described above
allows for flexible control of CSI reporting using a plurality of
channels (for example, a PUSCH and an sPUCCH).
<DCI for CSI Reporting Indication>
[0082] As the DCI for indicating CSI reporting to the UE, DCI for
data scheduling (a UL grant and/or a DL assignment) and/or DCI for
indicating a CSI trigger without scheduling data (DCI for CSI
trigger) can be used.
[0083] When both of the DCI for data scheduling and the DCI for CSI
trigger are supported, an identification field may be provided in
each of the pieces of DCI in order to distinguish the DCI for data
scheduling and the DCI for CSI trigger.
(Radio Communication System)
[0084] Hereinafter, a structure of a radio communication system
according to one embodiment of the present invention will be
described. In this radio communication system, the radio
communication method according to each embodiment of the present
invention described above may be used alone or may be used in
combination for communication.
[0085] FIG. 5 is a diagram to show an example of a schematic
structure of the radio communication system according to one
embodiment of the present invention. A radio communication system 1
can adopt carrier aggregation (CA) and/or dual connectivity (DC) to
group a plurality of fundamental frequency blocks (component
carriers) into one, where the system bandwidth in an LTE system
(for example, 20 MHz) constitutes one unit.
[0086] Note that the radio communication system 1 may be referred
to as "LTE (Long Term Evolution)," "LTE-A (LTE-Advanced)," "LTE-B
(LTE-Beyond)," "SUPER 3G," "IMT-Advanced," "4G (4th generation
mobile communication system)," "5G (5th generation mobile
communication system)," "FRA (Future Radio Access)," "New-RAT
(Radio Access Technology)," "NR (New Radio)," and so on, or may be
referred to as a system implementing these.
[0087] The radio communication system 1 includes a radio base
station 11 that forms a macro cell C1 of a relatively wide
coverage, and radio base stations 12 (12a to 12c) that form small
cells C2, which are placed within the macro cell C1 and which are
narrower than the macro cell C1. Also, user terminals 20 are placed
in the macro cell C1 and in each small cell C2. The arrangement of
each cell and user terminal 20 is by no means limited to the
arrangement shown in the diagram.
[0088] The user terminals 20 can connect with both the radio base
station 11 and the radio base stations 12. It is assumed that the
user terminals 20 use the macro cell C1 and the small cells C2 at
the same time by means of CA or DC. The user terminals 20 may adopt
CA or DC by using a plurality of cells (CCs) (for example, five or
less CCs, or six or more CCs).
[0089] Between the user terminals 20 and the radio base station 11,
communication can be carried out by using a carrier of a relatively
low frequency band (for example, 2 GHz) and a narrow bandwidth
(referred to as, for example, an "existing carrier," a "legacy
carrier" and so on). Meanwhile, between the user terminals 20 and
the radio base stations 12, a carrier of a relatively high
frequency band (for example, 3.5 GHz, 5 GHz, and so on) and a wide
bandwidth may be used, or the same carrier as that used between the
user terminals 20 and the radio base station 11 may be used. Note
that the structure of the frequency band for use in each radio base
station is by no means limited to these.
[0090] A wired connection (for example, an optical fiber in
compliance with the CPRI (Common Public Radio Interface), an X2
interface and so on) or a wireless connection may be established
between the radio base station 11 and the radio base stations 12
(or between two radio base stations 12).
[0091] The radio base station 11 and the radio base stations 12 are
each connected with a higher station apparatus 30, and are
connected with a core network 40 via the higher station apparatus
30. Note that the higher station apparatus 30 may be, for example,
access gateway apparatus, a radio network controller (RNC), a
mobility management entity (MME) and so on, but is by no means
limited to these. Also, each radio base station 12 may be connected
with the higher station apparatus 30 via the radio base station
11.
[0092] Note that the radio base station 11 is a radio base station
having a relatively wide coverage, and may be referred to as a
"macro base station," a "central node," an "eNB (eNodeB)," a
"transmitting/receiving point" and so on. The radio base stations
12 are radio base stations having local coverages, and may be
referred to as "small base stations," "micro base stations," "pico
base stations," "femto base stations," "HeNBs (Home eNodeBs),"
"RRHs (Remote Radio Heads)," "transmitting/receiving points" and so
on. Hereinafter, the radio base stations 11 and 12 will be
collectively referred to as "radio base stations 10," unless
specified otherwise.
[0093] Each of the user terminals 20 is a terminal that supports
various communication schemes such as LTE and LTE-A, and may
include not only mobile communication terminals (mobile stations)
but stationary communication terminals (fixed stations).
[0094] In the radio communication system 1, as radio access
schemes, orthogonal frequency division multiple access (OFDMA) is
applied to the downlink, and single carrier frequency division
multiple access (SC-FDMA) is applied to the uplink.
[0095] OFDMA is a multi-carrier communication scheme to perform
communication by dividing a frequency band into a plurality of
narrow frequency bands (subcarriers) and mapping data to each
subcarrier. SC-FDMA is a single carrier communication scheme to
mitigate interference between terminals by dividing the system
bandwidth into bands formed with one or continuous resource blocks
per terminal, and allowing a plurality of terminals to use mutually
different bands. Note that the uplink and downlink radio access
schemes are by no means limited to the combinations of these, and
other radio access schemes may be used.
[0096] In the radio communication system 1, different numerologies
may be applied within a cell and/or among cells. Note that the
numerology refers to, for example, communication parameters (for
example, a subcarrier spacing, a bandwidth, and so on) applied to
transmission and reception of a certain signal.
[0097] In the radio communication system 1, a downlink shared
channel (PDSCH (Physical Downlink Shared Channel), which is used by
each user terminal 20 on a shared basis, a broadcast channel (PBCH
(Physical Broadcast Channel)), downlink L1/L2 control channels and
so on, are used as downlink channels. User data, higher layer
control information, SIBs (System Information Blocks) and so on are
transmitted on the PDSCH. The MIBs (Master Information Blocks) are
transmitted on the PBCH.
[0098] The downlink L1/L2 control channels include a PDCCH
(Physical Downlink Control Channel), an EPDCCH (Enhanced Physical
Downlink Control Channel), a PCFICH (Physical Control Format
Indicator Channel), a PHICH (Physical Hybrid-ARQ Indicator Channel)
and so on. Downlink control information (DCI), including PDSCH and
PUSCH scheduling information, and so on are transmitted on the
PDCCH. The number of OFDM symbols to use for the PDCCH is
transmitted on the PCFICH. Transmission confirmation information
(for example, also referred to as "retransmission control
information," "HARQ-ACK," "ACK/NACK," and so on) of HARQ (Hybrid
Automatic Repeat reQuest) to a PUSCH is transmitted on the PHICH.
The EPDCCH is frequency-division multiplexed with the PDSCH
(downlink shared data channel) and used to transmit DCI and so on,
like the PDCCH.
[0099] In the radio communication system 1, an uplink shared
channel (PUSCH (Physical Uplink Shared Channel)), which is used by
each user terminal 20 on a shared basis, an uplink control channel
(PUCCH (Physical Uplink Control Channel)), a random access channel
(PRACH (Physical Random Access Channel)) and so on are used as
uplink channels. User data, higher layer control information and so
on are transmitted on the PUSCH. Further, downlink radio quality
information (CQI (Channel Quality Indicator)), transmission
confirmation information, and so on are transmitted on the PUCCH.
By means of the PRACH, random access preambles for establishing
connections with cells are transmitted.
[0100] In the radio communication system 1, a cell-specific
reference signal (CRS), a channel state information-reference
signal (CSI-RS), a demodulation reference signal (DMRS), a
positioning reference signal (PRS), and so on are transmitted as
downlink reference signals. In the radio communication system 1, a
measurement reference signal (SRS (Sounding Reference Signal)), a
demodulation reference signal (DMRS), and so on are transmitted as
uplink reference signals. Note that DMRS may be referred to as a
"user terminal specific reference signal (UE-specific Reference
Signal)." Transmitted reference signals are by no means limited to
these.
(Radio Base Station)
[0101] FIG. 6 is a diagram to show an example of an overall
structure of the radio base station according to one embodiment of
the present invention. A radio base station 10 includes a plurality
of transmitting/receiving antennas 101, amplifying sections 102,
transmitting/receiving sections 103, a baseband signal processing
section 104, a call processing section 105 and a transmission line
interface 106. Note that the radio base station 10 may be
configured to include one or more transmitting/receiving antennas
101, one or more amplifying sections 102 and one or more
transmitting/receiving sections 103.
[0102] User data to be transmitted from the radio base station 10
to the user terminal 20 by the downlink is input from the higher
station apparatus 30 to the baseband signal processing section 104,
via the transmission line interface 106.
[0103] In the baseband signal processing section 104, the user data
is subjected to transmission processes, such as a PDCP (Packet Data
Convergence Protocol) layer process, division and coupling of the
user data, RLC (Radio Link Control) layer transmission processes
such as RLC retransmission control, MAC (Medium Access Control)
retransmission control (for example, an HARQ transmission process),
scheduling, transport format selection, channel coding, an inverse
fast Fourier transform (IFFT) process, and a precoding process, and
the result is forwarded to each transmitting/receiving section 103.
Furthermore, downlink control signals are also subjected to
transmission processes such as channel coding and inverse fast
Fourier transform, and the result is forwarded to each
transmitting/receiving section 103.
[0104] The transmitting/receiving sections 103 convert baseband
signals that are pre-coded and output from the baseband signal
processing section 104 on a per antenna basis, to have radio
frequency bands and transmit the result. The radio frequency
signals having been subjected to frequency conversion in the
transmitting/receiving sections 103 are amplified in the amplifying
sections 102, and transmitted from the transmitting/receiving
antennas 101. The transmitting/receiving sections 103 can be
constituted with transmitters/receivers, transmitting/receiving
circuits or transmitting/receiving apparatus that can be described
based on general understanding of the technical field to which the
present invention pertains. Note that each transmitting/receiving
section 103 may be structured as a transmitting/receiving section
in one entity, or may be constituted with a transmitting section
and a receiving section.
[0105] Meanwhile, as for uplink signals, radio frequency signals
that are received in the transmitting/receiving antennas 101 are
amplified in the amplifying sections 102. The
transmitting/receiving sections 103 receive the uplink signals
amplified in the amplifying sections 102. The
transmitting/receiving sections 103 convert the received signals
into the baseband signal through frequency conversion and outputs
to the baseband signal processing section 104.
[0106] In the baseband signal processing section 104, user data
that is included in the uplink signals that are input is subjected
to a fast Fourier transform (FFT) process, an inverse discrete
Fourier transform (IDFT) process, error correction decoding, a MAC
retransmission control receiving process, and RLC layer and PDCP
layer receiving processes, and forwarded to the higher station
apparatus 30 via the transmission line interface 106. The call
processing section 105 performs call processing (setting up,
releasing and so on) for communication channels, manages the state
of the radio base station 10, manages the radio resources and so
on.
[0107] The transmission line interface 106 transmits and/or
receives signals to and/or from the higher station apparatus 30 via
a certain interface. The transmission line interface 106 may
transmit and/or receive signals (backhaul signaling) with other
radio base stations 10 via an inter-base station interface (for
example, an optical fiber in compliance with the CPRI (Common
Public Radio Interface) and an X2 interface).
[0108] The transmitting/receiving sections 103 transmit downlink
control information for indicating a trigger and/or activation of
channel state information. In this case, the transmitting/receiving
sections 103 transmit downlink control information including
information related to an uplink channel to be used for reporting
of the channel state information. Further, the
transmitting/receiving sections 103 receive channel state
information transmitted from the UE on a certain uplink
channel.
[0109] FIG. 7 is a diagram to show an example of a functional
structure of the radio base station according to one embodiment of
the present invention. Note that, the present example primarily
shows functional blocks that pertain to characteristic parts of the
present embodiment, and it is assumed that the radio base station
10 may include other functional blocks that are necessary for radio
communication as well.
[0110] The baseband signal processing section 104 at least includes
a control section (scheduler) 301, a transmission signal generation
section 302, a mapping section 303, a received signal processing
section 304, and a measurement section 305. Note that these
structures may be included in the radio base station 10, and some
or all of the structures do not need to be included in the baseband
signal processing section 104.
[0111] The control section (scheduler) 301 controls the whole of
the radio base station 10. The control section 301 can be
constituted with a controller, a control circuit or control
apparatus that can be described based on general understanding of
the technical field to which the present invention pertains.
[0112] The control section 301, for example, controls the
generation of signals in the transmission signal generation section
302, the mapping of signals by the mapping section 303, and so on.
The control section 301 controls the signal receiving processes in
the received signal processing section 304, the measurements of
signals in the measurement section 305, and so on.
[0113] The control section 301 controls scheduling (for example,
resource allocation) of system information, a downlink data signal
(for example, a signal transmitted on a PDSCH), and a downlink
control signal (for example, a signal transmitted on a PDCCH, an
EPDCCH, or an NR-PDCCH). Based on the results of determining
necessity or not of retransmission control to the uplink data
signal, or the like, the control section 301 controls generation of
a downlink control signal (for example, transmission confirmation
information and so on), a downlink data signal, and so on. The
control section 301 controls the scheduling of a synchronization
signal (for example, a PSS (Primary Synchronization Signal)/an SSS
(Secondary Synchronization Signal)), a downlink reference signal
(for example, a CRS, a CSI-RS, a DMRS), and so on.
[0114] The control section 301 controls scheduling of an uplink
data signal (for example, a signal transmitted on a PUSCH), an
uplink control signal (for example, a signal transmitted on a PUCCH
and/or a PUSCH), a random access preamble transmitted on a PRACH,
an uplink reference signal, and so on.
[0115] The control section 301 controls transmission of downlink
control information for indicating a trigger and/or activation of
channel state information. Further, the control section 301
controls generation of certain downlink control information (DCI
for CSI trigger) for indicating an uplink channel to be used for
reporting of the channel state information. In order to indicate an
uplink channel to be used for CSI reporting, the control section
301 performs control to generate DCI including a field for UL
channel identification, apply an RNTI associated with the uplink
channel, or change a DCI size based on the uplink channel.
[0116] The transmission signal generation section 302 generates
downlink signals (downlink control signals, downlink data signals,
downlink reference signals and so on) based on commands from the
control section 301 and outputs the downlink signals to the mapping
section 303. The transmission signal generation section 302 can be
constituted with a signal generator, a signal generation circuit or
signal generation apparatus that can be described based on general
understanding of the technical field to which the present invention
pertains.
[0117] For example, the transmission signal generation section 302
generates a DL assignment to report assignment information of a
downlink signal and a UL grant to report assignment information of
an uplink signal, based on commands from the control section 301.
For a downlink data signal, encoding processing and modulation
processing are performed in accordance with a coding rate,
modulation scheme, or the like determined based on channel state
information (CSI) from each user terminal 20.
[0118] The mapping section 303 maps the downlink signals generated
in the transmission signal generation section 302 to the certain
radio resources described above, based on commands from the control
section 301, and outputs these to the transmitting/receiving
sections 103. The mapping section 303 can be constituted with a
mapper, a mapping circuit or mapping apparatus that can be
described based on general understanding of the technical field to
which the present invention pertains.
[0119] The received signal processing section 304 performs
receiving processes (for example, demapping, demodulation, decoding
and so on) of received signals that are input from the
transmitting/receiving sections 103. Here, the received signals
are, for example, uplink signals that are transmitted from the user
terminals 20 (uplink control signals, uplink data signals, uplink
reference signals and so on). The received signal processing
section 304 can be constituted with a signal processor, a signal
processing circuit or signal processing apparatus that can be
described based on general understanding of the technical field to
which the present invention pertains.
[0120] The received signal processing section 304 outputs the
decoded information acquired through the receiving processes to the
control section 301. For example, if the received signal processing
section 304 receives the PUCCH including HARQ-ACK, the received
signal processing section 304 outputs the HARQ-ACK to the control
section 301. The received signal processing section 304 outputs the
received signals and/or the signals after the receiving processes
to the measurement section 305.
[0121] The measurement section 305 conducts measurements with
respect to the received signals. The measurement section 305 can be
constituted with a measurer, a measurement circuit or measurement
apparatus that can be described based on general understanding of
the technical field to which the present invention pertains.
[0122] The measurement section 305 may measure, for example,
received signal received power (for example, RSRP (Reference Signal
Received Power)), received quality (for example, RSRQ (Reference
Signal Received Quality) and an SINR (Signal to Interference plus
Noise Ratio)), uplink channel information (for example, CSI), and
so on. The measurement results may be output to the control section
301.
(User Terminal)
[0123] FIG. 8 is a diagram to show an example of an overall
structure of the user terminal according to one embodiment of the
present invention. A user terminal 20 includes a plurality of
transmitting/receiving antennas 201, amplifying sections 202,
transmitting/receiving sections 203, a baseband signal processing
section 204 and an application section 205. Note that the user
terminal 20 may be configured to include one or more
transmitting/receiving antennas 201, one or more amplifying
sections 202 and one or more transmitting/receiving sections
203.
[0124] Radio frequency signals that are received in the
transmitting/receiving antennas 201 are amplified in the amplifying
sections 202. The transmitting/receiving sections 203 receive the
downlink signals amplified in the amplifying sections 202. The
transmitting/receiving sections 203 convert the received signals
into baseband signals through frequency conversion, and output the
baseband signals to the baseband signal processing section 204. The
transmitting/receiving sections 203 can be constituted with
transmitters/receivers, transmitting/receiving circuits or
transmitting/receiving apparatus that can be described based on
general understanding of the technical field to which the present
invention pertains. Note that each transmitting/receiving section
203 may be structured as a transmitting/receiving section in one
entity, or may be constituted with a transmitting section and a
receiving section.
[0125] The baseband signal processing section 204 performs, on each
input baseband signal, an FFT process, error correction decoding, a
retransmission control receiving process, and so on. The downlink
user data is forwarded to the application section 205. The
application section 205 performs processes related to higher layers
above the physical layer and the MAC layer, and so on. In the
downlink data, broadcast information may be also forwarded to the
application section 205.
[0126] Meanwhile, the uplink user data is input from the
application section 205 to the baseband signal processing section
204. The baseband signal processing section 204 performs a
retransmission control transmission process (for example, an HARQ
transmission process), channel coding, precoding, a discrete
Fourier transform (DFT) process, an IFFT process and so on, and the
result is forwarded to the transmitting/receiving section 203. The
transmitting/receiving sections 203 convert the baseband signals
output from the baseband signal processing section 204 to have
radio frequency band and transmit the result. The radio frequency
signals having been subjected to frequency conversion in the
transmitting/receiving sections 203 are amplified in the amplifying
sections 202, and transmitted from the transmitting/receiving
antennas 201.
[0127] The transmitting/receiving sections 203 receive downlink
control information for indicating a trigger and/or activation of
channel state information. In this case, the transmitting/receiving
sections 203 receive downlink control information including
information related to an uplink channel to be used for reporting
of the channel state information. Further, the
transmitting/receiving sections 203 transmit channel state
information on a certain uplink channel.
[0128] FIG. 9 is a diagram to show an example of a functional
structure of the user terminal according to one embodiment of the
present invention. Note that, the present example primarily shows
functional blocks that pertain to characteristic parts of the
present embodiment, and it is assumed that the user terminal 20 may
include other functional blocks that are necessary for radio
communication as well.
[0129] The baseband signal processing section 204 provided in the
user terminal 20 at least includes a control section 401, a
transmission signal generation section 402, a mapping section 403,
a received signal processing section 404 and a measurement section
405. Note that these structures may be included in the user
terminal 20, and some or all of the structures do not need to be
included in the baseband signal processing section 204.
[0130] The control section 401 controls the whole of the user
terminal 20. The control section 401 can be constituted with a
controller, a control circuit or control apparatus that can be
described based on general understanding of the technical field to
which the present invention pertains.
[0131] The control section 401, for example, controls the
generation of signals in the transmission signal generation section
402, the mapping of signals by the mapping section 403, and so on.
The control section 401 controls the signal receiving processes in
the received signal processing section 404, the measurements of
signals in the measurement section 405, and so on.
[0132] The control section 401 acquires, from the received signal
processing section 404, a downlink control signal (for example, a
signal transmitted on the NR-PDCCH) and a downlink data signal (for
example, a signal transmitted on the PDSCH) that are transmitted
from the radio base station 10. The control section 401 controls
generation of an uplink control signal (for example, transmission
confirmation information and so on) and/or an uplink data signal,
based on the results of determining necessity or not of
retransmission control to a downlink control signal and/or a
downlink data signal.
[0133] The control section 401 controls reception of downlink
control information for indicating a trigger and/or activation of
channel state information. Further, the control section 401
performs control to determine an uplink channel to be used for
transmission of channel state information, based on the downlink
control information.
[0134] For example, the control section 401 may determine an uplink
channel to be used for transmission of channel state information,
based on at least one of a 1-bit bit field included in the downlink
control information, an RNTI applied to the downlink control
information, and the size of the downlink control information.
[0135] Further, the control section 401 may control an uplink
channel for performing power control command accumulation, based on
the uplink channel used for transmission of the channel state
information. Further, the control section 401 may apply a resource
allocation field included in the downlink control information to
the uplink channel determined based on the downlink control
information.
[0136] Further, the control section 401 may simultaneously receive
a plurality of pieces of downlink control information for
indicating a trigger and/or activation of channel state information
using the same or different uplink channel(s).
[0137] The transmission signal generation section 402 generates
uplink signals (uplink control signals, uplink data signals, uplink
reference signals and so on) based on commands from the control
section 401, and outputs the uplink signals to the mapping section
403. The transmission signal generation section 402 can be
constituted with a signal generator, a signal generation circuit or
signal generation apparatus that can be described based on general
understanding of the technical field to which the present invention
pertains.
[0138] For example, the transmission signal generation section 402
generates an uplink control signal about transmission confirmation
information, the channel state information (CSI), and so on, based
on commands from the control section 401. The transmission signal
generation section 402 generates uplink data signals, based on
commands from the control section 401. For example, when a UL grant
is included in a downlink control signal that is reported from the
radio base station 10, the control section 401 commands the
transmission signal generation section 402 to generate the uplink
data signal.
[0139] The mapping section 403 maps the uplink signals generated in
the transmission signal generation section 402 to radio resources,
based on commands from the control section 401, and outputs the
result to the transmitting/receiving sections 203. The mapping
section 403 can be constituted with a mapper, a mapping circuit or
mapping apparatus that can be described based on general
understanding of the technical field to which the present invention
pertains.
[0140] The received signal processing section 404 performs
receiving processes (for example, demapping, demodulation, decoding
and so on) of received signals that are input from the
transmitting/receiving sections 203. Here, the received signals
are, for example, downlink signals transmitted from the radio base
station 10 (downlink control signals, downlink data signals,
downlink reference signals and so on). The received signal
processing section 404 can be constituted with a signal processor,
a signal processing circuit or signal processing apparatus that can
be described based on general understanding of the technical field
to which the present invention pertains. The received signal
processing section 404 can constitute the receiving section
according to the present invention.
[0141] The received signal processing section 404 outputs the
decoded information acquired through the receiving processes to the
control section 401. The received signal processing section 404
outputs, for example, broadcast information, system information,
RRC signaling, DCI and so on, to the control section 401. The
received signal processing section 404 outputs the received signals
and/or the signals after the receiving processes to the measurement
section 405.
[0142] The measurement section 405 conducts measurements with
respect to the received signals. For example, the measurement
section 405 conducts measurement by using a downlink reference
signal transmitted from the radio base station 10. The measurement
section 405 can be constituted with a measurer, a measurement
circuit or measurement apparatus that can be described based on
general understanding of the technical field to which the present
invention pertains.
[0143] For example, the measurement section 405 may measure
received signal received power (for example, RSRP), a received
quality (for example, RSRQ, received SINR), downlink channel
information (for example, CSI), and so on. The measurement results
may be output to the control section 401.
(Hardware Structure)
[0144] Note that the block diagrams that have been used to describe
the above embodiments show blocks in functional units. These
functional blocks (components) may be implemented in arbitrary
combinations of hardware and/or software. Also, the means for
implementing each functional block is not particularly limited.
That is, each functional block may be realized by one piece of
apparatus that is physically and/or logically aggregated, or may be
realized by directly and/or indirectly connecting two or more
physically and/or logically separate pieces of apparatus (via wire
and/or wireless, for example) and using these plurality of pieces
of apparatus.
[0145] For example, a radio base station, a user terminal, and so
on according to one embodiment of the present invention may
function as a computer that executes the processes of the radio
communication method of the present invention. FIG. 10 is a diagram
to show an example of a hardware structure of the radio base
station and the user terminal according to one embodiment of the
present invention. Physically, the above-described radio base
station 10 and user terminals 20 may each be formed as computer
apparatus that includes a processor 1001, a memory 1002, a storage
1003, a communication apparatus 1004, an input apparatus 1005, an
output apparatus 1006, a bus 1007, and so on.
[0146] Note that, in the following description, the word
"apparatus" may be interpreted as "circuit," "device," "unit," and
so on. The hardware structure of the radio base station 10 and the
user terminals 20 may be designed to include one or a plurality of
apparatuses shown in the drawings, or may be designed not to
include part of pieces of apparatus.
[0147] For example, although only one processor 1001 is shown, a
plurality of processors may be provided. Furthermore, processes may
be implemented with one processor or may be implemented at the same
time, in sequence, or in different manners with one or more
processors. Note that the processor 1001 may be implemented with
one or more chips.
[0148] Each function of the radio base station 10 and the user
terminals 20 is implemented, for example, by allowing certain
software (programs) to be read on hardware such as the processor
1001 and the memory 1002, and by allowing the processor 1001 to
perform calculations to control communication via the communication
apparatus 1004 and control reading and/or writing of data in the
memory 1002 and the storage 1003.
[0149] The processor 1001 controls the whole computer by, for
example, running an operating system. The processor 1001 may be
configured with a central processing unit (CPU), which includes
interfaces with peripheral apparatus, control apparatus, computing
apparatus, a register, and so on. For example, the above-described
baseband signal processing section 104 (204), call processing
section 105, and so on may be implemented by the processor
1001.
[0150] Furthermore, the processor 1001 reads programs (program
codes), software modules, data, and so on from the storage 1003
and/or the communication apparatus 1004, into the memory 1002, and
executes various processes according to these. As for the programs,
programs to allow computers to execute at least part of the
operations of the above-described embodiments are used. For
example, the control section 401 of each user terminal 20 may be
implemented by control programs that are stored in the memory 1002
and that operate on the processor 1001, and other functional blocks
may be implemented likewise.
[0151] The memory 1002 is a computer-readable recording medium, and
may be constituted with, for example, at least one of a ROM (Read
Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM
(Electrically EPROM), a RAM (Random Access Memory), and other
appropriate storage media. The memory 1002 may be referred to as a
"register," a "cache," a "main memory (primary storage apparatus)"
and so on. The memory 1002 can store executable programs (program
codes), software modules, and the like for implementing the radio
communication method according to one embodiment of the present
invention.
[0152] The storage 1003 is a computer-readable recording medium,
and may be constituted with, for example, at least one of a
flexible disk, a floppy (registered trademark) disk, a
magneto-optical disk (for example, a compact disc (CD-ROM (Compact
Disc ROM) and so on), a digital versatile disc, a Blu-ray
(registered trademark) disk), a removable disk, a hard disk drive,
a smart card, a flash memory device (for example, a card, a stick,
and a key drive), a magnetic stripe, a database, a server, and
other appropriate storage media. The storage 1003 may be referred
to as "secondary storage apparatus."
[0153] The communication apparatus 1004 is hardware
(transmitting/receiving device) for allowing inter-computer
communication via a wired and/or wireless network, and may be
referred to as, for example, a "network device," a "network
controller," a "network card," a "communication module," and so on.
The communication apparatus 1004 may be configured to include a
high frequency switch, a duplexer, a filter, a frequency
synthesizer, and so on in order to realize, for example, frequency
division duplex (FDD) and/or time division duplex (TDD). For
example, the above-described transmitting/receiving antennas 101
(201), amplifying sections 102 (202), transmitting/receiving
sections 103 (203), transmission line interface 106, and so on may
be implemented by the communication apparatus 1004.
[0154] The input apparatus 1005 is an input device that receives
input from the outside (for example, a keyboard, a mouse, a
microphone, a switch, a button, a sensor, and so on). The output
apparatus 1006 is an output device that allows sending output to
the outside (for example, a display, a speaker, an LED (Light
Emitting Diode) lamp, and so on). Note that the input apparatus
1005 and the output apparatus 1006 may be provided in an integrated
structure (for example, a touch panel).
[0155] Furthermore, these types of apparatus, including the
processor 1001, the memory 1002, and others, are connected by a bus
1007 for communicating information. The bus 1007 may be formed with
a single bus, or may be formed with buses that vary between pieces
of apparatus.
[0156] Also, the radio base station 10 and the user terminals 20
may be structured to include hardware such as a microprocessor, a
digital signal processor (DSP), an ASIC (Application Specific
Integrated Circuit), a PLD (Programmable Logic Device), an FPGA
(Field Programmable Gate Array), and so on, and part or all of the
functional blocks may be implemented by the hardware. For example,
the processor 1001 may be implemented with at least one of these
pieces of hardware.
(Variations)
[0157] Note that the terminology described in this specification
and/or the terminology that is needed to understand this
specification may be replaced by other terms that convey the same
or similar meanings. For example, "channels" and/or "symbols" may
be "signals" ("signaling"). Also, "signals" may be "messages." A
reference signal may be abbreviated as an "RS," and may be referred
to as a "pilot," a "pilot signal," and so on, depending on which
standard applies. Furthermore, a "component carrier (CC)" may be
referred to as a "cell," a "frequency carrier," a "carrier
frequency" and so on.
[0158] A radio frame may be constituted of one or a plurality of
periods (frames) in the time domain. Each of one or a plurality of
periods (frames) constituting a radio frame may be referred to as a
"subframe." Furthermore, a subframe may be constituted of one or a
plurality of slots in the time domain. A subframe may be a fixed
time length (for example, 1 ms) independent of numerology.
[0159] Furthermore, a slot may be constituted of one or a plurality
of symbols in the time domain (OFDM (Orthogonal Frequency Division
Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division
Multiple Access) symbols, and so on). Furthermore, a slot may be a
time unit based on numerology. A slot may include a plurality of
mini-slots. Each mini-slot may be constituted of one or a plurality
of symbols in the time domain. A mini-slot may be referred to as a
"sub-slot."
[0160] A radio frame, a subframe, a slot, a mini-slot, and a symbol
all express time units in signal communication. A radio frame, a
subframe, a slot, a mini-slot, and a symbol may each be called by
other applicable terms. For example, one subframe may be referred
to as a "transmission time interval (TTI)," a plurality of
consecutive subframes may be referred to as a "TTI" or one slot or
one mini-slot may be referred to as a "TTI." That is, a subframe
and/or a TTI may be a subframe (1 ms) in existing LTE, may be a
shorter period than 1 ms (for example, 1 to 13 symbols), or may be
a longer period than 1 ms. Note that a unit expressing TTI may be
referred to as a "slot," a "mini-slot," and so on instead of a
"subframe."
[0161] Here, a TTI refers to the minimum time unit of scheduling in
radio communication, for example. For example, in LTE systems, a
radio base station schedules the allocation of radio resources
(such as a frequency bandwidth and transmission power that are
available for each user terminal) for the user terminal in TTI
units. Note that the definition of TTIs is not limited to this.
[0162] TTIs may be transmission time units for channel-encoded data
packets (transport blocks), code blocks, and/or codewords, or may
be the unit of processing in scheduling, link adaptation, and so
on. Note that, when TTIs are given, the time interval (for example,
the number of symbols) to which transport blocks, code blocks,
and/or codewords are actually mapped may be shorter than the
TTIs.
[0163] Note that, in the case where one slot or one mini-slot is
referred to as a TTI, one or more TTIs (that is, one or more slots
or one or more mini-slots) may be the minimum time unit of
scheduling. Furthermore, the number of slots (the number of
mini-slots) constituting the minimum time unit of the scheduling
may be controlled.
[0164] A TTI having a time length of 1 ms may be referred to as a
"normal TTI" (TTI in LTE Rel. 8 to Rel. 12), a "long TTI," a
"normal subframe," a "long subframe" and so on. A TTI that is
shorter than a normal TTI may be referred to as a "shortened TTI,"
a "short TTI," a "partial or fractional TTI," a "shortened
subframe," a "short subframe," a "mini-slot," a "sub-slot" and so
on.
[0165] Note that a long TTI (for example, a normal TTI, a subframe,
and so on) may be interpreted as a TTI having a time length
exceeding 1 ms, and a short TTI (for example, a shortened TTI and
so on) may be interpreted as a TTI having a TTI length shorter than
the TTI length of a long TTI and equal to or longer than 1 ms.
[0166] A resource block (RB) is the unit of resource allocation in
the time domain and the frequency domain, and may include one or a
plurality of consecutive subcarriers in the frequency domain. Also,
an RB may include one or a plurality of symbols in the time domain,
and may be one slot, one mini-slot, one subframe, or one TTI in
length. One TTI and one subframe each may be constituted of one or
a plurality of resource blocks. Note that one or a plurality of RBs
may be referred to as a "physical resource block (PRB (Physical
RB))," a "sub-carrier group (SCG)," a "resource element group
(REG)," a "PRB pair," an "RB pair" and so on.
[0167] Furthermore, a resource block may be constituted of one or a
plurality of resource elements (REs). For example, one RE may
correspond to a radio resource field of one subcarrier and one
symbol.
[0168] Note that the above-described structures of radio frames,
subframes, slots, mini-slots, symbols, and so on are merely
examples. For example, structures such as the number of subframes
included in a radio frame, the number of slots per subframe or
radio frame, the number of mini-slots included in a slot, the
numbers of symbols and RBs included in a slot or a mini-slot, the
number of subcarriers included in an RB, the number of symbols in a
TTI, the symbol length, the cyclic prefix (CP) length, and so on
can be variously changed.
[0169] Also, the information, parameters, and so on described in
this specification may be represented in absolute values or in
relative values with respect to certain values, or may be
represented in another corresponding information. For example,
radio resources may be specified by certain indices. Further,
mathematical formulas using these parameters and so on may be
different from those explicitly disclosed in this
specification.
[0170] The names used for parameters and so on in this
specification are in no respect limiting. For example, since
various channels (PUCCH (Physical Uplink Control Channel), PDCCH
(Physical Downlink Control Channel), and so on) and information
elements can be identified by any suitable names, the various names
allocated to these various channels and information elements are in
no respect limiting.
[0171] The information, signals, and so on described in this
specification may be represented by using any of a variety of
different technologies. For example, data, instructions, commands,
information, signals, bits, symbols, chips, and so on, all of which
may be referenced throughout the herein-contained description, may
be represented by voltages, currents, electromagnetic waves,
magnetic fields or particles, optical fields or photons, or any
combination of these.
[0172] Also, information, signals, and so on can be output from
higher layers to lower layers, and/or from lower layers to higher
layers. Information, signals, and so on may be input and/or output
via a plurality of network nodes.
[0173] The information, signals, and so on that are input and/or
output may be stored in a specific location (for example, a memory)
or may be managed by using a management table. The information,
signals, and so on to be input and/or output can be overwritten,
updated, or appended. The information, signals, and so on that are
output may be deleted. The information, signals, and so on that are
input may be transmitted to another apparatus.
[0174] Reporting of information is by no means limited to the
aspects/embodiments described in this specification, and other
methods may be used as well. For example, reporting of information
may be implemented by using physical layer signaling (for example,
downlink control information (DCI), uplink control information
(UCI), higher layer signaling (for example, RRC (Radio Resource
Control) signaling, broadcast information (master information block
(MIB), system information blocks (SIBs), and so on), MAC (Medium
Access Control) signaling and so on), and other signals and/or
combinations of these.
[0175] Note that physical layer signaling may be referred to as
"L1/L2 (Layer 1/Layer 2) control information (L1/L2 control
signals)," "L1 control information (L1 control signal)," and so on.
Also, RRC signaling may be referred to as an "RRC message," and can
be, for example, an RRC connection setup (RRCConnectionSetup)
message, an RRC connection reconfiguration
(RRCConnectionReconfiguration) message, and so on. Also, MAC
signaling may be reported using, for example, MAC control elements
(MAC CEs).
[0176] Also, reporting of certain information (for example,
reporting of "X holds") does not necessarily have to be performed
explicitly, and can be reported implicitly (by, for example, not
reporting this certain information or reporting another piece of
information).
[0177] Determinations may be made in values represented by one bit
(0 or 1), may be made in Boolean values that represent true or
false, or may be made by comparing numerical values (for example,
comparison against a certain value).
[0178] Software, whether referred to as "software," "firmware,"
"middleware," "microcode," or "hardware description language," or
called by other terms, should be interpreted broadly to mean
instructions, instruction sets, code, code segments, program codes,
programs, subprograms, software modules, applications, software
applications, software packages, routines, subroutines, objects,
executable files, execution threads, procedures, functions, and so
on.
[0179] Also, software, commands, information, and so on may be
transmitted and received via communication media. For example, when
software is transmitted from a website, a server, or other remote
sources by using wired technologies (coaxial cables, optical fiber
cables, twisted-pair cables, digital subscriber lines (DSL), and so
on) and/or wireless technologies (infrared radiation, microwaves,
and so on), these wired technologies and/or wireless technologies
are also included in the definition of communication media.
[0180] The terms "system" and "network" used in this specification
can be used interchangeably.
[0181] In the present specification, the terms "base station (BS),"
"radio base station," "eNB," "gNB," "cell," "sector," "cell group,"
"carrier," and "component carrier" may be used interchangeably. A
base station may be referred to as a "fixed station," "NodeB,"
"eNodeB (eNB)," "access point," "transmission point," "receiving
point," "femto cell," "small cell" and so on.
[0182] A base station can accommodate one or a plurality of (for
example, three) cells (also referred to as "sectors"). When a base
station accommodates a plurality of cells, the entire coverage area
of the base station can be partitioned into multiple smaller areas,
and each smaller area can provide communication services through
base station subsystems (for example, indoor small base stations
(RRHs (Remote Radio Heads))). The term "cell" or "sector" refers to
part of or the entire coverage area of a base station and/or a base
station subsystem that provides communication services within this
coverage.
[0183] In the present specification, the terms "mobile station
(MS)," "user terminal," "user equipment (UE)," and "terminal" may
be used interchangeably. A base station may be referred to as a
"fixed station," "NodeB," "eNodeB (eNB)," "access point,"
"transmission point," "receiving point," "femto cell," "small cell"
and so on.
[0184] A mobile station may be referred to, by a person skilled in
the art, as a "subscriber station," "mobile unit," "subscriber
unit," "wireless unit," "remote unit," "mobile device," "wireless
device," "wireless communication device," "remote device," "mobile
subscriber station," "access terminal," "mobile terminal,"
"wireless terminal," "remote terminal," "handset," "user agent,"
"mobile client," "client," or some other appropriate terms in some
cases.
[0185] Furthermore, the radio base stations in this specification
may be interpreted as user terminals. For example, each
aspect/embodiment of the present invention may be applied to a
configuration in which communication between a radio base station
and a user terminal is replaced with communication among a
plurality of user terminals (D2D (Device-to-Device)). In this case,
the user terminals 20 may have the functions of the radio base
stations 10 described above. In addition, wording such as "uplink"
and "downlink" may be interpreted as "side." For example, an uplink
channel may be interpreted as a side channel.
[0186] Likewise, the user terminals in this specification may be
interpreted as radio base stations. In this case, the radio base
stations 10 may have the functions of the user terminals 20
described above.
[0187] Specific actions which have been described in this
specification to be performed by a base station may, in some cases,
be performed by upper nodes. In a network including one or a
plurality of network nodes with base stations, it is clear that
various operations that are performed to communicate with terminals
can be performed by base stations, one or more network nodes (for
example, MMEs (Mobility Management Entities), S-GW
(Serving-Gateways), and so on may be possible, but these are not
limiting) other than base stations, or combinations of these.
[0188] The aspects/embodiments illustrated in this specification
may be used individually or in combinations, which may be switched
depending on the mode of implementation. The order of processes,
sequences, flowcharts, and so on that have been used to describe
the aspects/embodiments herein may be re-ordered as long as
inconsistencies do not arise. For example, although various methods
have been illustrated in this specification with various components
of steps in exemplary orders, the specific orders that are
illustrated herein are by no means limiting.
[0189] The aspects/embodiments illustrated in this specification
may be applied to LTE (Long Term Evolution), LTE-A (LTE-Advanced),
LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation
mobile communication system), 5G (5th generation mobile
communication system), FRA (Future Radio Access), New-RAT (Radio
Access Technology), NR(New Radio), NX (New radio access), FX
(Future generation radio access), GSM (registered trademark)
(Global System for Mobile communications), CDMA 2000, UMB (Ultra
Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE
802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB
(Ultra-WideBand), Bluetooth (registered trademark), systems that
use other adequate radio communication methods and/or
next-generation systems that are enhanced based on these.
[0190] The phrase "based on" (or "on the basis of") as used in this
specification does not mean "based only on" (or "only on the basis
of"), unless otherwise specified. In other words, the phrase "based
on" (or "on the basis of") means both "based only on" and "based at
least on" ("only on the basis of" and "at least on the basis
of").
[0191] Reference to elements with designations such as "first,"
"second" and so on as used herein does not generally limit the
quantity or order of these elements. These designations may be used
herein only for convenience, as a method for distinguishing between
two or more elements. Thus, reference to the first and second
elements does not imply that only two elements may be employed, or
that the first element must precede the second element in some
way.
[0192] The term "judging (determining)" as used herein may
encompass a wide variety of actions. For example, "judging
(determining)" may be interpreted to mean making "judgments
(determinations)" about calculating, computing, processing,
deriving, investigating, looking up, (for example, searching a
table, a database, or some other data structures), ascertaining,
and so on. Furthermore, "judging (determining)" may be interpreted
to mean making "judgments (determinations)" about receiving (for
example, receiving information), transmitting (for example,
transmitting information), input, output, accessing (for example,
accessing data in a memory), and so on. In addition, "judging
(determining)" as used herein may be interpreted to mean making
"judgments (determinations)" about resolving, selecting, choosing,
establishing, comparing, and so on. In other words, "judging
(determining)" may be interpreted to mean making "judgments
(determinations)" about some action.
[0193] The terms "connected" and "coupled," or any variation of
these terms as used herein mean all direct or indirect connections
or coupling between two or more elements, and may include the
presence of one or more intermediate elements between two elements
that are "connected" or "coupled" to each other. The coupling or
connection between the elements may be physical, logical, or a
combination thereof. For example, "connection" may be interpreted
as "access." When being used in this specification, two elements
may be considered "connected" or "coupled" to each other by using
one or more electrical wires, cables and/or printed electrical
connections, and, as some non-limiting and non-inclusive examples,
by using electromagnetic energy having wavelengths in radio
frequency regions, microwave regions and/or (both visible and
invisible) optical regions, or the like.
[0194] When terms such as "including," "comprising," and variations
of these are used in this specification or in claims, these terms
are intended to be inclusive, in a manner similar to the way the
term "provide" is used. Furthermore, the term "or" as used in this
specification or in claims is intended to be not an exclusive
disjunction.
[0195] Now, although the present invention has been described in
detail above, it should be obvious to a person skilled in the art
that the present invention is by no means limited to the
embodiments described in this specification. The present invention
can be implemented with various corrections and in various
modifications, without departing from the spirit and scope of the
present invention defined by the recitations of claims.
Consequently, the description in this specification is provided
only for the purpose of explaining examples, and should by no means
be construed to limit the present invention in any way.
(Supplementary Note)
[0196] Supplementary notes on the present disclosure are described
below.
[0197] The present disclosure relates to control of a UL channel
(or a resource) to be used for transmission of aperiodic CSI
(A-CSI) when aperiodic CSI reporting (A-CSI reporting) is triggered
using downlink control information (DCI). For example, when CSI is
triggered using DCI, 1 bit indicating whether the CSI is
transmitted on an uplink shared channel (for example, a PUSCH) or
transmitted on an uplink control channel (for example, an sPUCCH)
is included in the DCI.
[0198] For example, whether the aperiodic CSI is transmitted on the
PUSCH or the short PUCCH (sPUCCH) can be determined based on at
least one of a bit field of a certain bit (for example, 1 bit)
included in the DCI (for example, a UL grant), an RNTI applied to
the DCI, the size of the DCI (for example, a DCI payload
length).
[0199] TPC command accumulation may be controlled based on whether
the aperiodic CSI is transmitted on the PUSCH or the short PUCCH.
For example, the UE controls TPC command accumulation for the PUSCH
and TPC command accumulation for the PUCCH, based on whether the
aperiodic CSI is transmitted on the PUSCH or the short PUCCH.
[0200] Interpretation of a resource allocation field (RA field)
included in the DCI may be determined, based on whether the
aperiodic CSI is transmitted on the PUSCH or the short PUCCH. For
example, when CSI transmission using the PUSCH is indicated, the UE
applies the RA field to the PUSCH. Otherwise (for example, when CSI
transmission using the PUCCH is indicated), the UE may apply the RA
field to the short PUCCH.
[0201] The UE may simultaneously receive a plurality of A-CSI
triggers in the same serving cell. In this case, one of the
plurality of triggers may be an A-CSI trigger using the PUSCH, and
the other triggers may be A-CSI triggers using the short PUCCH.
Further, the plurality of A-CSI triggers may be individually
notified using a plurality of different pieces of DCI, or may be
notified using one piece of DCI.
[0202] Supplementary notes about examples of structures of the
present disclosure are described below. Note that the present
invention is not limited to the structures described below.
[Structure 1]
[0203] A user terminal including: [0204] a receiving section that
receives downlink control information indicating a trigger and/or
activation of channel state information; and [0205] a control
section that determines an uplink channel to be used for
transmission of the channel state information, based on the
downlink control information.
[Structure 2]
[0206] The user terminal according to structure 2, wherein [0207]
the control section determines the uplink channel to be used for
transmission of the channel state information, based on at least
one of a 1-bit bit field included in the downlink control
information, an RNTI applied to the downlink control information,
and a size of the downlink control information.
[Structure 3]
[0208] The user terminal according to structure 1 or 2, wherein
[0209] the control section controls an uplink channel for
performing power control command accumulation, based on the uplink
channel used for transmission of the channel state information.
[Structure 4]
[0210] The user terminal according to any one of structures 1 to 3,
wherein [0211] the control section applies a resource allocation
field included in the downlink control information to the uplink
channel determined based on the downlink control information.
[Structure 5]
[0212] The user terminal according to any one of structures 1 to 4,
wherein [0213] the receiving section simultaneously receives a
plurality of pieces of downlink control information indicating a
trigger and/or activation of channel state information using same
or different uplink channel(s).
[Structure 6]
[0214] A radio communication method for a user terminal, the radio
communication method including: [0215] receiving downlink control
information indicating a trigger and/or activation of channel state
information; and [0216] determining an uplink channel to be used
for transmission of the channel state information, based on the
downlink control information.
[0217] The present application is based on Japanese Patent
Application No. 2017-239055, filed on Nov. 27, 2017. The contents
of the application are incorporated herein by reference.
* * * * *